On my planar 3 with the rb 300 tonearm it sounds very good. I should mention that I haven't used any really expensive cartridges. I've heard some in othes' systems, and soon came to realize that the differences my ears could make out were not worth the (ongoing) cost of 'High-End' carts and styli.
For the cost, I find the Mp110 well worth it. I also run a Shure M91 ED (Aftermarket Stylus) on a stock AR-XA, and an Ortofon 2Mred on an Optonica 7205. Prior to the Nag I was using a Ortofon OM 30 on the rega and I was satisfied with the detail retrieval and tracking ability that I was getting, as well as the overall sound (although it was a smidgen on the bright side for my taste.)
I find the Mp110 to be very smooth, with more than sufficient bass (for me) and amazingly revealing for the cost. Also it is an absolutely masterful tracker, with very little surface noise (something that I found rather distasteful in the OM 30 in this set-up). I think what I like most about the MP110 is the mid-range presentation. I'm a mid-range guy more than a base-head and this cartridge does a superb job with its' midrange presentation. I did quite like the OM 30 on my Optonica deck (moreso than the 2Mred) so I am planing on switching those two out.
Hope that helps.